B3 Enzymes Flashcards
What are the two types of protein?
Fibrous and Globular
Describe the Induced Fit Model?
An enzyme’s active site and substrate are not complimentary, the substrate binds to the active site to form an enzyme-substrate complex and the active site changes shape to become complimentary. The active site puts pressure on bonds which reduces the activation energy.
How does temperature affect enzymes?
As the temperature increases there is more kinetic energy so there are more successful collisions. Therefore more enzyme-substrate complexes are formed. However when the temperature rises to a certain point the hydrogen and ionic bonds break which causes the tertiary structure to change so the active site is no longer complimentary.
How does pH affect enzymes?
Increased pH alters the charge on amino acids which breaks the ionic bonds between the R groups. The tertiary structure is changed and the shape of the active site is no longer complimentary to the substrate , so no e-s complexes.
What is pH a measure of?
Hydrogen ion concentration
How does substrate concentration affect an enzyme?
As substrate concentration rises it is a limiting factor so there is empty active sites. As the line levels enzymes active sites are the limiting factor as there is not enough.
What are immobilised enzymes?
An enzyme that is attached to an inert, insoluble material such as calcium alginate
What are the positives of immobilised enzymes?
They can be reused, it is a continuous process and the temperature and pH can be kept constant
What are the two types of inhibitors?
Non-competitive and competitive
What is an inhibitor?
An inhibitor reduces the rate of an enzyme’s reaction by interfering with it in some way.
What does a competitive inhibitor do?
It has a similar shape to the substrate and binds to the active site which prevents enzyme-substrate complexes from forming (temporary effect)
What does a non-competitive inhibitor do?
It binds to the allosteric site of the enzyme which changes the tertiary structure therefore the active site’s shape is changed so it is no longer complimentary to the substrate. No binding so no e-s complexes (permanent effect).
